I haven't found a good and succinct description of what the -ck patch set does and that I could link to here, but here's what it says on the Arch -ck page:

"..many Archers elect to use this package for the BFS' excellent desktop interactivity and responsiveness under any load situation. Additionally, the bfs imparts performance gains beyond interactivity"

I don't know if there are objective benchmarks that one can use to demonstrate an improvement in 'responsiveness and interactivity'. Subjectively, however, I feel that there's a slight improvement. You decide for yourself.

You might now be asked a long series of questions about how the kernel should be configured (or you might not be -- depending on what kernel version you're currently running). In MOST cases you can select the default option (i.e. hit enter) but you should still read each question and consider it. Making a mistake won't break your computer, so don't be scared.

The new stuff
I know it's a bit lazy to simply post the questions as I do below, but...well, I don't have much of an excuse other than you having to figure out for yourself what you want to enable, and what you don't.: